1. Field of the Invention
The present invention relates generally to a system for sharpening chain saw teeth, and more particularly, to a system for both sharpening the cutting edge and grinding down the forward post of individual chain saw teeth.
2. Description of the Prior Art
Generally, each cutting tooth of a chain saw is provided with a forward post (also referred to as a depth gauge) at the front end of the tooth and a cutting edge at the rear end. For efficient operation, it is necessary both (1) that the cutting edge be sharpened at a particular angle relative to the axis of the chain and (2) that the proper vertical offset be provided between the forward post and the cutting edge. The particular angle and offset specified will vary depending on the type of chain saw and the type of chain saw blade.
In recent years, rotary grinders have found widespread application in sharpening the cutting edge of chain saw teeth at the desired angle. See, for example, U.S. Pat. Nos. 4,242,926; 4,019,407; 4,002,089; 3,738,200; and 3,354,753. In particular, U.S. Pat. No. 4,002,089 discloses a grinder having an adjustable plate which rests on the cutting edges of adjacent teeth of the chain saw blade while one cutting edge is being ground. The ability to adjust the relative height of the grinder wheel to the cutting edge allows wheels having differing diameters to be utilized. U.S. Pat. No. 3,738,200 discloses a grinder similar to that of U.S. Pat. No. 4,002,089, differing in the structure of the mechanism for adjusting the height of the grinder wheel relative to the adjustable plate. Grinders having adjustable plates for resting on the top of individual chain saw teeth are available from Granberg, Ltd., Richmond, CA.